Electrical connecting conductor



p 16, 1947. M. D. BERGAN 2,427,518

ELECTRICAL CONNECTING CONDUCTOR Filed March 28, 1945 Fig.1

Fig.3 NH

INVENTOR. MARTIN D. BERGAN ATTORNEY Patented Sept. 16, 1947 2,427,518ELECTRICAL CONNECTING CONDUCTOR Martin D. Bergan, Westfield, N. J., as.

The Thomas & Betts 00., Elizabeth,

or to J., a

corporation of New Jersey Application March @8, 1945, Serial No. 585,245

1 Claim. 1

This invention relates to solderless electrical connectors embodying ahomogeneous joint between a connector and a stranded cable by which toproduce a. low resistance electrical connection of rugged form and highmechanical pull-out value.

A purpose of the invention is to produce an Electrical ConnectingConductor, embodying a connector member which may be used with andcompressively bonded onto an electrical cable, especially of thestranded type. as for example, stranded straight-lay cable and strandedropelay cable and which. by the new method herein, may be satisfactorilyjoined thereto by compression dies in such manner that the normal lay ornatural position of the cable strands remains unaltered and free fromkinking strain and rupture when the connector is installed on the cableand throughout the life of the bonded solderless joint.

Furthermore, an important purpose is to produce an electrical connectorof such characteristics that the individual wires and the cable strandcomposed thereof are enveloped in a separate wall of ductile metal whichcold-flows by compression into the interstices of the plurality of wiresconstituting each strand of the cable, thereby greatly increasing themechanical and electrical bond of the joint in various types ofelectrical connectors. such as terminals, splices, taps, and otherconnectors to which the principle of this invention is applicable andfound advantageous over previous forms of solderless joints.

Diiliculty is experienced with conventional practice in securing aneffective solderless joint between each individual wire of a strand andthe connector, which is a problem inherent in the lack of means to bondthe individual wires with the connector. The features of this inventionsupply such a need and provide means for sealing in the separate wiresand bonding them as a strand into a connector.

The construction disclosed herein shows exemplary types of cable, asabove mentioned, and a lug type terminal, as one form of electricalconnector, produced in accordance with this invention for such cables,by which to illustrate the advantages and utility of the new electricalconnector and conductor assembly.

The accompanying drawings illustrate the invention, present it in amanner preferred at this time, explain the features thereof in order toportray the scope of the invention by which to more readily demonstrateother embodiments which may develop out of the teachings of thisspecification, and aid in understanding the problems sought to besolved.

The description and. drawings herein explain the principle of theinvention and present the best mode contemplated in applying suchprinciple, so as to distinguish the invention from others; and there isparticularly pointed out and claimed, the part, improvement orcombination, which constitutes the invention or discovery, as understoodby -a comparison thereof with the prior art.

Figs. 1 thru 5 show the invention adapted to stranded rope-lay cable,while Fig. 8 shows stranded straight-lay cable, as examples of a varietyof cable types to which the invention may be adapted.

Fig. 1 shows a side view of an electrical terminal, while Fig. 2 is anend view thereof looking from the line 2-2.

Fig. 3 shOWS a sectional view as developed along the line 3-3, whileFig. 4 shows a cross section on the line 4l.

Fig. 5 shows the strands of a rope-lay cable placed in position withinthe several bores of the connector before making the bonded solderlessjoint by compression.

Fig. 6 shows an end view, that is, a cable end view, of the connectorplaced between two dies before compression.

Fig. 7 shows the dies under compression to produce a solderless joint ofbonded homogeneous formation. The cable and connector in these twoviews, in effect, may be regarded as showing, diagrammatically, a crosssection on the line 6'l, except that the connector and the cable show areduction in size due to the compression.

Fig. 8 shows aside view of a completed conductor, after removing it fromthe compression dies, thus being reduced to its final size. It is seenthat a triple straight-lay cable is joined 'with the connector member,in a manner similar to the previous views. Any number of cables orstrands may be joined with the connector and individually embraced inseparate metallic portions thereof to form the new joint in accordancewith this invention.

Referring now more particularly to the drawings for a detaileddescription of the invention, the connector chosen for illustrationcomprise a terminal or lug connector usually made of copper. Thisconnector includes a hub ill in which a cable is secured, and anintegral lug tongue or bar II having a hole I2 for installing theconnector and its electrical cable in service position. The perforatedtongue or bar H merely represents one outer end toward the tongue II,and a group of concentrically arranged outer bores i are also formed inthe hub Ill around the center bore. The bores H and I5 may have solid orclosed bottoms, while their outer ends are open. The outer series orbores 15 are shown formed at an angle to the end face orplane of the hubID, that is, at an angle to the line 22. Thus while the cable receivingsocket or bore I 4 is disposed on the axis or the hub Hi, the outercircle of bores I5 is directed at an angle to the end face of the hubIII to conform with the angle of the lead, that is, the angle of thespiral strands of a ropelay cable for which the illustrated connector isproduced.

The outer series of angular bores l5 are spaced from each other and alsofrom the center bore i4 sufficiently to leave an internal cylindricalwall of ductile metal I6 between all outer bores as well as between thelatter and the center bore. This feature is important in connection withthe particular type of joint attained in accordance with this invention,that is, the sealing in of separate wires, and the bonding of eachindividual strand composed of said separate wires, into the metal bodyof the connector Ill, II.

The well known type of rope-lay cable is shown in Fig. 5, and itconsists of a central linear or straight core strand i1 and severalouter spiral strands l8. End views of this and other types of cable maybe regarded as being shown in Figs. 6 and 7. It will be noted that thepitch or lead angle of the outer bores IS in the connector hub l0conforms with the pitch or lead angle of the outer spiral strands l8 ofthe rope-lay cable. Each strand I1 and I8 is pocketed into theindividual bores I4 and I5, respectively, of the hub I0.

In assembling the connector hub ID with the rope-lay cable, the outerstrands iii are slightly separated from each other as well as from thecenter or core strand l1 and are all introduced, respectively, into thebores 14 and I5. In other words, the center cable strand I1 is disposedin the central bore I4, and the outer spiral strands I8 are insertedinto the outer angular bores l5.

The terminal and cable thus assembled (Fig. 5) is next placed in orbetween compression dies 20 (Fig. 6), and the latter are closed tocompress or swage the metal of the hub l0 and of the cable strands I1and i8 together, under great pressure, into a homogeneous mass (Fig. 7).Thus the ductile metal of the internal walls l6, and of the wiresforming a strand, cold-flow into an integrated homogeneous mass, andform a continuous electrical current path. The pressure of the dies(Fig. 7) makes a complete Joint, as shown in side view Fig. 8.

When the dies 20 are closed (Fig. 7) the internal ductile walls I 6 ofthe hub l0, which separate the plurality of bores l4 and i5, cold flowinto the interstices (formed by the individual wires) of the cablestrands l1, l8 and thus produce a coldwelded joint of homogeneous formby reason of the ductility of the cable wires and copper hub Ill. Thegreat pressure applied by the dies seals the separate Wires and theindividual strands into the connector, so that in effect the metal ofthe wires 4 and connector integrate into one bonded mass. The innermostcore wire or a strand is likewise sealed in the mass by virtue oibonding with contiguous wires constitutin said strand,

InFig. 8 there is shown a, simple straight lay cable, that is, aplurality of individual cables 2| having their ends placed in aconnector sleeve or hub 22 having an equal number of straight boresformed parallel. This arrangement likewise provides, as hereinbeforeexplained, an internal metallic wall 23 between and surrounding eachcable end 2|. When compressed by the dies 20, a bonded joint of lowelectrical resistance, and capable of enduring high mechanical stress,is produced, as explained and shown in connection with previous views ofthe drawings and the method therein shown.

It will be noted that, in each example of the invention discussed, theends of the cable strands I1, [8 and 2| are separated by definitespacing where they enter the connector members Ill and 22. Thischaracteristic of the new electrical conductor and connector providesfor full length internal separating annular walls 16 of ductile metal toembrace individually each strand portion of the cable, that is, theentire length thereof which is introduced into the connector hub ID.Accordingly, the individual wires constituting a strand are sealed intothe connector against corrosive effect for the life of the conductor,this being one of the important problems solved by the invention.

This invention is presented to fill the need for a useful electricalconnecting conductor. Various modifications in construction, mode ofoperation, use and method, may and often do occur to others skilled inthe art, especially so after acquaintance with an invention.Accordingly, this disclosure is exemplary of the principles andequivalents without being limited to the present showing of theinvention.

What is claimed is:

An electrical connecting conductor comprising, in combination, aconnector having a hub to which is fitted a rope-lay cable, a centralbore in which is held the core strand of said ropelay cable, a seriesof'outer bores provided symmetrically in the hub around the central boreand in which outer bores are held the outer strands of said rope-laycable, annular walls of ductile metal defining each separate bore, therope-lay cable having all of its strands separated at their entry intothe hub, with the strands placed individually in the bores, by which theannular walls maintain the strands in separately spaced relation, andthe hub being compressed and the respective annular walls of ductilemetal coldflowed under pressure into the interstices of the individualstrands.

MARTIN D. BERGAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,064,831 Hawksley Dec. 22, 1936650,861 McTighe June 5, 1900 1,759,567 Dibner "a May 20, 1930 614,839Cleveland Nov. 29, 1898

